O.Thetford, P.Gray German Aircraft of the First World War (Putnam)

Rumpler 4A 15 This first Rumpler Grossflugzeuge appeared in March 1915 and became the prototype for the later G I. The machine made a test climb, carrying ten personnel, to an altitude of 3,200 m. on 15th March 1915, and later the same day attained a height of 1,800 m. while carrying sixteen personnel. On 17th April 1915 this prototype was destroyed. Engines, two 150 h.p. Benz Bz III. Span, 18.75 m. (61 ft. 6 1/4 in.). Length, 11.8 m. (38 ft. 8 5/8 in.).

Rumpler G II (5A 16) This machine differed little from the G I and, as far as can be ascertained, was virtually the same aircraft fitted with more powerful 220 h.p. Benz Bz IV engines. Armament, one Parabellum machine-gun in nose cockpit and one aft of wings.

It appears that the Gotha and Friedrichshafen firms are not having a monopoly in twin-engined bombers, the above illustrations showing a machine produced by the Rumpler firm. - From the numbers painted on the fuselage it appears that this machine was built as long ago as 1915.

Because of their heavy defensive armament, the Kagohl's first twin-engined G types of aircraft were used singly for reconnaissance duties, and when accompanying a number of smaller two-seaters on a bombing raid the inclusion of a G type guaranteed that enemy fighters would concentrate on the big machine, leaving the main bomb-carrying force almost unmolested. But a hot reception awaited the attackers. This Rumpler G II (107/15) is seen over the Eastern Front, operating with Kagohl II from Kowel aerodrome in 1916.

The success of the Rumpler G II at the Front during 1916 led to the development of the Rumpler G III powered by two Mercedes D IVa 260hp engines, but the aircraft had constructional shortcomings and could not compete with the designs of AEG, Friedrichshafen and Gotha, the main suppliers of twin-engined G types. From a limited production batch, the Rumpler G III was used only in small numbers by the Kagohl, reaching a maximum at the Front of ten machines at the end of October 1917.